Lesson 4 of 4

Wi-Fi web server

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// Switch the LED on GPIO4 from a web page #include <WiFi.h> #include <WebServer.h> const char* SSID = "bench-lab"; const char* PASS = "robotics"; // the bench-lab network's password const uint8_t LED_PIN = 4; const uint8_t RGB_PIN = 38; WebServer server(80); void handleRoot() { server.send(200, "text/html", "<h1>ESP32-S3</h1><a href=\"/on\">LED on</a> <a href=\"/off\">LED off</a>"); } void setup() { Serial.begin(115200); pinMode(LED_PIN, OUTPUT); WiFi.mode(WIFI_STA); // join a network as a station WiFi.begin(SSID, PASS); Serial.print("Connecting to "); Serial.println(SSID); while (WiFi.status() != WL_CONNECTED) { rgbLedWrite(RGB_PIN, 0, 0, 64); // blue blink while connecting delay(250); rgbLedWrite(RGB_PIN, 0, 0, 0); delay(250); Serial.print("."); } Serial.println(); Serial.print("Connected, IP "); Serial.println(WiFi.localIP().toString()); rgbLedWrite(RGB_PIN, 0, 64, 0); // green: on the network server.on("/", handleRoot); server.on("/on", []() { digitalWrite(LED_PIN, HIGH); server.send(200, "text/plain", "LED on"); Serial.println("GET /on"); }); server.on("/off", []() { digitalWrite(LED_PIN, LOW); server.send(200, "text/plain", "LED off"); Serial.println("GET /off"); }); server.begin(); } void loop() { server.handleClient(); // answer requests, never block here }

Stopped · Your code isn't running yet. Until you press Run, the board runs the program already on it.

Nothing printed yet. Press Run.

Join a 2.4 GHz network, print the board's IP address and switch the LED from a phone's browser. The RGB LED shows the Wi-Fi state.

A web page served by the board
Status on the RGB LED
Wi-Fi bursts need a good USB supply

Pin	Connects to	What it does
`GPIO4`	330 Ω, then the LED	Switched from the web page
`GPIO38`	RGB LED D6	Wi-Fi status

Wire it in

Sensors and actuators this board drives, with the real connections.

All 10 parts on the ESP32-S3-DevKitC-1 page

Wi-Fi web server

Try it yourself

Serial monitor

Checks

Break it

Inputs

Parameters

Wire it in

Wi-Fi web server

Try it yourself

Serial monitor

Checks

Break it

Inputs

Parameters

Wire it in